CVE-2026-33354: AVideo has an authenticated arbitrary local file read via `chunkFile` path injection in `aVideoEncoder.json.php`

POST /objects/aVideoEncoder.json.php accepts a requester-controlled chunkFile parameter intended for staged upload chunks. Instead of restricting that path to trusted server-generated chunk locations, the endpoint accepts arbitrary local filesystem paths that pass isValidURLOrPath(). That helper allows files under broad server directories including /var/www/, the application root, cache, tmp, and videos, only rejecting .php files.

For an authenticated uploader editing their own video, this becomes an arbitrary local file read. The endpoint copies the attacker-chosen local file into the attacker’s public video storage path, after which it can be downloaded over HTTP.

I confirmed this locally by creating an attacker-owned video, then calling aVideoEncoder.json.php with videos_id=<own video>, format=mp4, and chunkFile=/var/www/html/AVideo/.compose/letsencrypt/live/localhost/privkey.pem. The resulting public video URL returned the local TLS private key and began with -----BEGIN PRIVATE KEY-----.